Tray for heat treating furnaces



Juile 23,1942. H, L A'N' 2,287,740

TRAY FOR HEAT TREATING FURNACES I Filed April 8, 1941 4 Sheets-Sheet 1 w b I A 75 3 /5 U "ii: A I /Z /5 w I I0 /5 F 4&

June 23, 1942. KLOUMAN 2,287,740

TRAY FOR HEAT TREATING FURNACES Filed April 8, 1941 4 Sheets-Sheet 3 IN VENTOR.

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ATTORNEYS.

June 23, 1942. H. KLOUMAN 2,287,740

TRAY FOR I XEAT TREATING FURNACES Filed April 8, 1941 4 Sheets-Sheet 4 III! III/I Patented June 23, 1942 2,287,740 TRAY FOR HEAT TREATING FURNACES- Iienning Klouman, Mich to Michiana Products City, Ind., a corporation igan City, Ind., assignor Corporation, Michigan of Indiana Application April 8, 1941, Serial No. 387,397

6 Claims. (Q1. 263-47) In the heat treatment of forgings, castings, ceramics and such like, there is much diificulty with the trays for carrying the material through thefurnaces which, in familiar form, are oblong with doors at the ends and traversed by a track formed of rollers or rails.

The trays are repeatedly subjected to the treatment and must be able to support heavy loads at while resting temperatures on the order of 1700 on or being pushed along the roller or rail tracks that are out of alignment vertically or laterally or both. The trays are thus subjected to severe ringing strains while the strength of the metal is much impaired by the high heat.

The trays are used in series end to end, the length of the furnace. As a cool tray is pushed into the furnace its forward end is subject to heat approximating the maximum in the furnace, while its rear end, or that next to the door' is relatively little heated. When a tray reaches the last position in the furnace the conditions are somewhat reversed. The consequent unequal heating causes uneven expansion and contraction in the tray.

The principal object of this invention is to provide a tray structure including lengthwise and crosswise pieces or members having suificient looseness of connection to allow for expansion and contraction and to permit accommodation to irregularities in the track while being held against going askew or awry. Generally speaking, this is accomplished by using side pieces at all times held in proper spaced relation to form a support, or base, and several cross pieces side by side, spanning the side pieces and loosely connected with them.

Further objects and advantages of the invention will appear as the disclosure proceeds and the description is read in connection with the accompanying drawings showing selected embodiments of the invention and in which Fig. 1 is a perspective view of one form of base or support used in making a tray structure;

Fig. 2 is a perspective view of one of several cross pieces for spanning the support shown in Fig. 1;

Fig. 3 is a perspective view tray structure;

Fig. 4 is a plan View of the same;

Figs. 5, 6 and 7am sectional views taken on the lines 5, 66 and l---'! of Fig. 4;

Fig. 8 is a perspective view of a different embodiments of the tray structure in the process of assembly;

of the assembled Fig. 9 is a perspective view of the finished tray structure;

Fig. 10 is a plan view of this modified form with parts broken away at the upper right corner;

Figs. 11, 12 and '13 are sectional views taken on the lines H-! l, [2-H and !3I3 of Fig. 10. In Fig. 1 the side pieces l0 and H are shown as inverted channels cast integral with the flanges l2 of an intermediate cross piece It connecting the medial portions of the side pieces. At each end each side piece has an upwardly directed flange [4 extending to the level of the surface of the cross piece l3. At each side each channel has a laterally directed flange notched to provide lugs or teeth IE to cooperate with hooked portions It in the flanges ll of other channel shaped cross pieces l8, fitted between the cross piece l3 and the flanges Hi.

In assembling, the cross pieces It may be lowered into position a little bit at one side of their final position and then pushed laterally to bring the hooked portions l6 into interlocking relation with the lugs or teeth l5. The last two cross pieces l8 will have the hooked portions completed by welding to the flanges ll, bars l9, as best illustrated in Fig. 6. This is necessary in order to permit the last two cross pieces to be lowered directly into final position.

The side pieces I0 and II will be supported on the rollers or rails forming the track through the furnace and the general H-shape formation of these side pieces and theintermediate cross piece l3 gives suflicient flexibility to accommodate ordinary irregularities in the track without imposing destructive strains on the metal. The structure, however, will insure that the side pieces remain in proper spaced relation and in substantial register, by which is meant that the ends remain in alignment or in the initial position while the tray is being pushed through the furnace.

Without some means for maintaining the side pieces l0 and II properly spaced and in register, pushing a tray into the furnace and moving the whole line of trays forward may easily cause a distortion or skewing of a tray sufiicient to bring one rail into lateral engagement with the track rail or roller. When this occurs with one tray it is very likely to be repeated as the next tray is pushed into the furnace, with the result that there is excessive binding imposing unnecessary strains on the tray structure and sometimes causing an upset of the whole line.

The engagements between the hooked portions N5 of the cross pieces l8 and the lugs I5 is sufiiciently loose to allow for all the expansion and some rocking of a cross piece with respect to the side pieces, in order to prevent concentration of strain as the tray rests on the track or is being moved along through the furnace.

In Fig. 8 the side pieces 20 and 2| are of inverted channel shape and at each end there is an upstanding flange 22, corresponding to the flange I4, Fig. 1. At one side of each piece 20 and 2| there are three lugs 23, 24 and 25, having openings 28 in alignment.

The two side pieces are connected together and maintained in proper relation by an intermediate piece 21 in the form of a plate having lateral arms 28 at each end, provided with spaced lugs 29, having openings 30, corresponding to openings 26, all of which are adapted to receive tie rods 3|, as best illustrated in Fig. 10.

The cross pieces 32 are of inverted channel form and each flange 34 is provided with a notch 33 to receive one of the side members 20 or 2|. Inwardly from each notch 33 the flanges 34 are provided with openings 35, corresponding to the openings 26 and 3|], and aligned with them, when the parts are assembled as illustrated in Fig. 10, from which it will appear that the rods 3| serve to connect the side pieces both to the intermediate piece and to each of the cross pieces.

With holes one-half inch in diameter and rods seven sixteenths of an inch in diameter it has been found that the assembly can be readily made in ordinary course of manufacture and the parts will have about the correct allowance for movement in accommodating the tray to inequalities of the track and allowing for expansion without being objectionably loose for purposes of handling.

In the trays here illustrated the design is for side pieces twenty-four inches long and cross pieces twenty-two and one-quarter inches long. The parts are, of course, made of heat resisting alloy and are strengthened by appropriate fillets, gussets and ribs, as shown, but detailed description of which will be omitted for the sake of clearness.

It will be obvious that some will prefer the use of rods and perforated lugs to secure the cross pieces to the side pieces and such a change will be readily made in the forms shown on Figs. 1 to 7. Specific decription and illustration are omitted to avoid prolixity.

I claim:

1. In a device of the class described, spaced parallel side pieces having lateral projections between their ends, and flanges projecting upwardly at their ends above the level of the lateral projections, and a plurality of cross pieces loosely connected with said lateral projections, the end cross pieces being limited by the upward projections against movement lengthwise of the device.

2. In a device of the class described, spaced supporting side pieces, a plurality of cross pieces supported on the side pieces, means for loosely connecting the cross pieces and side pieces to allow limited relative movement, and connecting means between the side pieces to maintain them in proper spaced relation and restrain one of them from advancing with respect to the other.

3. In a device of the class described, spaced supporting side pieces, a plurality of cross pieces supported on the side pieces, means for loosely connecting the cross pieces and side pieces to allow limited relative movement and means to prevent skewing the cross pieces with respect to the side pieces.

4. In a device of the class described, spaced side pieces, a cross piece rigidly connecting the medial portions of the side pieces, and other cross pieces loosely carried by the side pieces at each side of the first mentioned cross piece.

5. A tray for heat treating furnaces comprising spaced side pieces, means carried by said side pieces for connecting said side pieces together and for holding the latter spaced apart sidewise and in register lengthwise, and a plurality of cross-pieces spanning the side pieces and loosely connected with them.

6. In a heat treating furnace having supporting guideways for conducting trays therethrough, a tray comprising supports at the sides thereof for engaging said guideways, means including cross-pieces loosely connecting said supports together to form a slightly flexible platform, said means being so constructed and arranged as to hold said side supports in spaced relation and prevent one side of the tray from advancing ahead of the other while said tray is moving along the supporting guideway but providing for relative upward and downward movement of the guideway-engaging portions of said supports.

HENNING KLOUMAN. 

